Omicron is turning out to be a Grinch this holiday season, with the fast-spreading coronavirus variant causing some flights to be canceled this Christmas. 
As of 6 a.m. EST Friday, Delta Air Lines has canceled 52 flights on Christmas Day while United Airlines has canceled 47. More flights have been canceled on Christmas Eve: 168 from United and 115 from Delta, according to flight tracker FlightAware.
Both United and Delta said a spike in omicron infections among crew members played a part in the cancellations.
“The nationwide spike in Omicron cases this week has had a direct impact on our flight crews and the people who run our operation. As a result, we’ve unfortunately had to cancel some flights. … We’re sorry for the disruption,” according to a statement from United spokesperson Josh Freed.
Freed added that United is notifying impacted customers and rebooking “as many people as possible.” 
A Delta statement shared with USA TODAY said the flight cancellations were caused by a “combination of issues, including but not limited to, potential inclement weather in some areas and the impact of the Omicron variant.”
The airline went on to say that it “exhausted all options and resources” before canceling flights for Friday. 
“We apologize to our customers for the delay in their holiday travel plans. Delta people are working hard to get them to where they need to be as quickly and as safely as possible on the next available flight,” the statement reads.
NERVOUS ABOUT TRAVEL (AGAIN?)What to know about airline, hotel and cruise cancellation policies as omicron surges
‘CURRENT HOLD TIME’:Christmas flight cancellations send travelers scrambling
TRAVELING FOR THE HOLIDAYS?Here are the worst times to hit the road.
The cancellations come as some airline industry leaders urge the Centers for Disease Control and Prevention to update its guidance on how long fully vaccinated people with a breakthrough infection should self-isolate.
Current CDC guidance says 10 days, but JetBlue, Delta and airline industry trade group Airlines for America have each sent letters asking for a reduced isolation period. Delta and Airlines for America are pushing for five days with a negative test. 
“The Omicron surge may exacerbate personnel shortages and create significant disruptions to our workforce and operations,” Airlines for America CEO Nick Calio wrote in a Thursday letter to the CDC. “Much has changed since the initial guidance was developed and issued in 2020 and we believe that variables such as vaccine rates, improved treatments and mask mandates should be considered as the pandemic and science continue to evolve.”
Not all agree. The Association of Flight Attendants-CWA, which represents roughly 50,000 flight attendants at 17 airlines, wrote to the CDC to voice support for the 10-day isolation period.
“We recognize that how long a person should isolate is not a ‘one-size-fits-all’ number of days. We also note that fully vaccinated people may be less infectious for less time than unvaccinated people. Still, we consider your current 10-day recommendation to represent a prudent middle ground,” reads a Thursday letter signed by Association of Flight Attendants-CWA International President Sara Nelson. “We do not see the justification for reducing the number of days at this time.”
Follow USA TODAY reporter Bailey Schulz on Twitter: @bailey_schulz. 

source